Projects supported by this grant will investigate the function of the corneal nerves. One aspect of this study will use psychophysical methods to determine the effects of contact lens wear on corneal sensitivity and what underlying physiological conditions are responsible for the observed changes. Other experiments will use sensory recording techniques from the ciliary nerves to characterize these axons by neurophysiological data such as modality responsiveness, receptive field and dynamic range. Another area of investigation will be that of trophic interactions in the cornea between the epithelial cells and the corneal nerves. This work will focus on determining what physiological and anatomical changes occur in the epithelium when the influences of the corneal nerves are removed. Anatomical studies of the corneal nerve endings, which presumably contain the receptor membrane, will use electron microscopical methods to establish the anatomical characteristics of the receptor terminals and to determine if specialized contacts exist between the nerve terminals and epithelial cells.